Numerical integration of the incrementally non-linear, zero elastic range, bounding surface plasticity model for sand

SANISAND-Z is a recently developed plasticity model for sands with zero purely elastic range in stress space within the framework of Bounding Surface (BS) plasticity. As a consequence of zero elastic range the plastic strain increment direction, and consequently the elastic-plastic moduli fourth order tensor depends on the direction of the stress increment, rendering the model incrementally non-linear and intrinsically implicit. An iterative algorithm based on the Backward Euler method is presented to solve the non-linear system of ordinary differential equations. A non-traditional consistency condition based on the plastic multiplier is introduced as a core element of the system. A thorough analysis of the stability and accuracy of the algorithm is presented based on error estimation. The proposed integration scheme allows the use of SANISAND-Z framework in Finite Element Analysis

Incident detection using data from social media

This is an accepted manuscript of an article published by IEEE in 2017 IEEE 20th International Conference on Intelligent Transportation Systems (ITSC) on 15/03/2018, available online: https://ieeexplore.ieee.org/document/8317967/citations#citations The accepted version of the publication may differ from the final published version.© 2017 IEEE. Due to the rapid growth of population in the last 20 years, an increased number of instances of heavy recurrent traffic congestion has been observed in cities around the world. This rise in traffic has led to greater numbers of traffic incidents and subsequent growth of non-recurrent congestion. Existing incident detection techniques are limited to the use of sensors in the transportation network. In this paper, we analyze the potential of Twitter for supporting real-time incident detection in the United Kingdom (UK). We present a methodology for retrieving, processing, and classifying public tweets by combining Natural Language Processing (NLP) techniques with a Support Vector Machine algorithm (SVM) for text classification. Our approach can detect traffic related tweets with an accuracy of 88.27%.Published versio

Traffic event detection framework using social media

This is an accepted manuscript of an article published by IEEE in 2017 IEEE International Conference on Smart Grid and Smart Cities (ICSGSC) on 18/09/2017, available online: https://ieeexplore.ieee.org/document/8038595 The accepted version of the publication may differ from the final published version.© 2017 IEEE. Traffic incidents are one of the leading causes of non-recurrent traffic congestions. By detecting these incidents on time, traffic management agencies can activate strategies to ease congestion and travelers can plan their trip by taking into consideration these factors. In recent years, there has been an increasing interest in Twitter because of the real-time nature of its data. Twitter has been used as a way of predicting revenues, accidents, natural disasters, and traffic. This paper proposes a framework for the real-time detection of traffic events using Twitter data. The methodology consists of a text classification algorithm to identify traffic related tweets. These traffic messages are then geolocated and further classified into positive, negative, or neutral class using sentiment analysis. In addition, stress and relaxation strength detection is performed, with the purpose of further analyzing user emotions within the tweet. Future work will be carried out to implement the proposed framework in the West Midlands area, United Kingdom.Published versio

A characterization of almost continuity and weak continuity

summary:It is well known that a function $f$ from a space $X$ into a space $Y$ is continuous if and only if, for every set $K$ in $X$ the image of the closure of $K$ under $f$ is a subset of the closure of the image of it. In this paper we characterize almost continuity and weak continuity by proving similar relations for the subsets $K$ of $X$

Engineering soil barriers to minimise annual shrinkage/swelling in plastic clays

Engineered soil barriers have been proposed to prevent rainwater infiltration into the underlying soil, thus improving stability of sloping ground. The use of engineered barriers on flat ground as means of preventing flooding has also been explored. This paper aims to provide proof-of-concept as to the potential efficiency of engineered barriers in minimising soil shrinkage and swelling arising from seasonal variations of water content and pore water pressures within the ground due to its interaction with the atmosphere. A series of 2-dimensional, hydro-mechanically coupled finite element analyses were conducted to this effect. Emphasis was placed on accurately modelling the stiffness of the underlying soil, accounting for its small-strain behaviour, as well as the hydraulic behaviour of all the layers involved. The results confirm that it is possible to engineer barriers to minimise shrinkage/swelling in greenfield, as well as urban, conditions and highlight the influence of barrier geometry and configuration, so that recommendations for the design of such barriers can be made

Modelling of undrained shearing of soft natural clays

stress-strain response of soft natural clays is characterised by anisotropy, destructuration and rate-dependency. An accurate constitutive description of these materials should take into consideration all of the characteristics above. In this paper, two constitutive models for soft soils, namely the SCLAY1S and Creep-SCLAY1S models are used to simulate the undrained response of two soft natural clays, Gothenburg clay from Sweden and Otaniemi clay from Finland. The SCLAY1S model accounts for the effect of inherent and induced anisotropy and destructuration, while the Creep-SCLAY1S accounts also for the creep and rate effects. The model simulations are compared against triaxial compression and extension tests on anisotropically consolidated samples. The results demonstrate the need to incorporate all features represented in the Creep-SCLAY1S model when modelling structured natural clays

AVALIAÇÃO DAS CONDIÇÕES BIOCLIMÁTICAS DA REGIÃO COSTEIRA DO NORDESTE BRASILEIRO: O MUNICÍPIO DE FORTALEZA, CE

A fim de identificar diretrizes que promovam um melhoramento das condições térmicas ao nível do pedestre, o presente estudo analisa o comportamento horário e mensal das variáveis bioclimáticas do município de Fortaleza, cidade litorânea de clima predominantemente quente e úmido durante todo o ano, por meio da aplicação do índice Voto Médio Estimado (PMV). A partir da análise dos resultados, verifica-se que o horário de maior desconforto acontece às 13h durante o Solstício de Verão, gerando extremo estresse fisiológico, com mais de 80% da população insatisfeita. Também é verificada a preferência térmica da população, por meio da aplicação de questionários. Os resultados coincidem com os valores analisados e indicam o sombreamento e a ventilação como recursos necessários à minimização das condições térmicas externas